The use of retractable awnings has become widespread. They are commonly used to provide shelter from the elements for outdoor spaces such as patios. They can also be employed to lower energy bills by shading windows of dwellings, and are widely installed on campers and motor homes to provide protection from the elements for a patio area immediately adjacent thereto. Their retractable design is particularly important to the camper and mobile home application as it is critical that they be easily stowed while the camper or mobile home is in motion.
One important concern users of awnings have, both fixed and retractable, is control of rainwater as it sheds from the top surface of the awning. Awnings are typically deployed such that their top surfaces are declined at a downward angle from their point of attachment to a structure. This facilitates shedding of rainwater to the lower end of the awning and prevents water from pooling on the top of the awning. As with pitched roofs on buildings, without a gutter system of some kind, water can quickly pool and splash around the perimeter of the awning. This can cause problems such as erosion, mud splatter, and even flooding of the very area the awning is intended to shield from the rain.
Gutter systems of various designs similar to those employed on the roofs of buildings have been adapted for use in conjunction with awnings in the past to help collect and divert the shedding rainwater away from the perimeter of the awning. Such a gutter system, however, is really only practical when applied to awnings that are intended to be permanently (or at least semi-permanently) deployed. Any conventional gutter system design that is applied to a retractable awning will interfere with its easy retraction and stowing. At the very least, a typical gutter system would have to be detached and disassembled first every time a retractable awning is to be retracted and stowed away. Likewise, the gutter system would have to be re-assembled and re-affixed whenever the awning is re-deployed. Thus, this additional assembly and dis-assembly of a gutter system tends to negate the convenience that a retractable awning is designed to provide, and such systems are therefore not commonly used with retractable awnings.
One simple technique commonly employed by users of retractable awnings, in an attempt to minimize impact of rainwater as it is shed from the awning during a rain shower or storm, is to tilt the awning to one corner on the downward end of the awning. This at least causes the flow of the shedding rainwater to be substantially directed to one location of the awning's perimeter, rather than being permitted to shed from all downward edges of the awning. This can be accomplished by simply adjusting a supporting member, typically provided at each corner of the tilted end of the awning, such that one support member is shorter than the other. This causes the top surface of the awning to tilt to the corner having the shorter support member.
While this technique is helpful in some ways, it still does not solve the problems outlined above, and in fact may exacerbate some of them. For example, pooling of water and erosion can be much worse, albeit limited to one location, when virtually all of the rainwater is shed to a more limited area of the awning's perimeter.